title: Effects on mitochondria of mitochondria-induced nitric oxide release from a ruthenium nitrosyl complex.
abstract: The ruthenium nitrosyl complex trans-[Ru(NO)(NH(3))(4)(py)](PF(6))(3) (pyNO), a nitric oxide (NO) donor, was studied in regard to the release of NO and its impact both on isolated mitochondria and HepG2 cells. In isolated mitochondria, NO release from pyNO was concomitant with NAD(P)H oxidation and, in the 25-100 microM range, it resulted in dissipation of mitochondrial membrane potential, inhibition of state 3 respiration, ATP depletion and reactive oxygen species (ROS) generation. In the presence of Ca(2+), mitochondrial permeability transition (MPT), an unspecific membrane permeabilization involved in cell necrosis and some types of apoptosis, was elicited. As demonstrated by externalization of phosphatidylserine and activation of caspase-9 and caspase-3, pyNO (50-100 microM) induced HepG2 cell death, mainly by apoptosis. The combined action of the NO itself, the peroxynitrite yielded by NO in the presence of reactive oxygen species (ROS) and the oxidative stress generated by the NAD(P)H oxidation is proposed to be involved in cell death by pyNO, both via respiratory chain inhibition and ROS levels increase, or even via MPT, if Ca(2+) is present.
authors.affiliation: Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. Café s/n, 14040-903 Ribeirão Preto, SP, Brazil.
authors.forename: Cezar R
authors.initials: CR
authors.lastname: Pestana
authors.forename: Daniela P S
authors.initials: DP
authors.lastname: Phelippin
authors.forename: Ana C M
authors.initials: AC
authors.lastname: Polizello
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Dorta
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Uyemura
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Santos
authors.forename: Fábio G
authors.initials: FG
authors.lastname: Doro
authors.forename: Fernando P
authors.initials: FP
authors.lastname: Rodrigues
authors.forename: Elia
authors.initials: E
authors.lastname: Tfouni
authors.forename: Carlos
authors.initials: C
authors.lastname: Curti
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000378:metabolism; D000083162:Mitochondrial Permeability Transition Pore; D008933:Mitochondrial Swelling / Q000187:drug effects; D019255:NADPH Oxidases / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009942:Organometallic Compounds / Q000494:pharmacology*; D010084:Oxidation-Reduction; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D012428:Ruthenium / Q000494:pharmacology*
chemical_list: D033681:Mitochondrial Membrane Transport Proteins; D000083162:Mitochondrial Permeability Transition Pore; D020030:Nitric Oxide Donors; D009942:Organometallic Compounds; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D012428:Ruthenium; D000255:Adenosine Triphosphate; D019255:NADPH Oxidases; D020169:Caspases